RESUMO
<p><b>OBJECTIVE</b>To study the feasibility and clinical efficacy of a minimally invasive sinus tarsi approach in the treatment of Sanders II calcaneus fractures.</p><p><b>METHODS</b>From August of 2015 to July of 2016, 13 patients(totally 13 feet) with Sanders II intra-articular calcaneus fractures were treated via the minimally invasive sinus tarsi approach. The Böhler angle, Gissane angle and the length, width and height of calcaneus were compared between pre-operation and post-operation. The AOFAS ankle and foot scoring system of the orthopaedic ankle foot Association was used to evaluate the efficacy.</p><p><b>RESULTS</b>All the patients were followed up, and the duration ranged from 6 to 15 months, with an average of 9.5 months. No incision complications occurred. The Böhler angle was increased from preoperative (18.82±5.11)° to postoperative(26.63±4.45)°(=-4.16,=0.000). The Gissane angle was increased from preoperative(111.07±15.36)° to postoperative (124.56±8.71)° (=-2.75,=0.011). The length, width, height of calcaneus were absolutely improved from preoperative(69.82±5.95) mm, (42.07±3.68) mm, (41.20±3.90) mm to preoperatively(72.61±5.46) mm, (39.10±4.02) mm, (44.03±3.33) mm. According to the AOFAS, 8 patients got an excellent result, 4 good and 1 poor, and the postoperative mean score was 88.2±5.9.</p><p><b>CONCLUSIONS</b>The limited open sinus tarsi approach could be used successfully to treat displaced Sanders II fractures with less injury and effectively restored the surface of subtalar joint, however the method is not fit for the patients with comminuted fracture in lateral wall and great change in the length, width, height, varus and valgus of calcaneus.</p>
RESUMO
Anticoagulation factor II (ACF II) isolated from the venom of Agkistrodon acutus is an activated coagulation factor X-binding protein in a Ca(2+)-dependent fashion with marked anticoagulant activity. The equilibrium unfolding of rare earth ions (RE(3+))-reconstituted ACF II in guanidine hydrochloride (GdnHCl) solution was studied by fluorescence. The GdnHCl-induced unfolding of RE(3+) (Nd(3+), Sm(3+), Eu(3+), Gd(3+))-reconstituted ACF II follows a three-state transition with a stable intermediate state. Substitutions of the RE(3+) ions for Ca(2+) in ACF II decrease the conformational stability of its native state but markedly increase the conformational stability of its intermediate state. The free energy change of RE(3+)-ACF II from the intermediate state to denatured state linearly increases with the increase of ionic potentials of bound metal ions (Ca(2+), Nd(3+), Sm(3+), Eu(3+), and Gd(3+)). The refolding of ACF II from the unfolded state to the intermediate state can be induced merely by adding 10 microM RE(3+) ions without changing the concentration of the denaturant. The kinetic results of the RE(3+)-induced refolding provide evidence indicating that the intermediate state of RE(3+)-ACF II consists of at least two refolding phases and that the refolding rate constant values of the faster phase decrease with the increase of the difference between the radii of Ca(2+) and RE(3+), but the refolding rate constant values of the slower phase are similar to each other. The results of this study indicate that the size of metal ion is the major factor responsible for the metal ion-induced conformational stabilization of the native ACF II, while the metal ionic potential plays a predominant role in stabilizing the conformation for the intermediate state.
